Volkswagen Repair: rotor & break pad replacements, rear drum brakes, vw cabrio

Question
I have a 99 VW Cabrio, vin # is: 3vwdb61eb8xm809601
And me scenerio is:
I recently got all four rotors and brake pads replaced, and since on and off I've had this problem when I brake sometimes where there's a vibration in the brake pedal and a noise that sounds like a spring being tapped or pulled loose ( a 'boing' sound like you hear in cartoons) Sorry don't know how else to describe it. And these some resistance when that happens in the breaks, but the car still breaks fine, just sounds bad. The past couple days when this has happened, there is also a slight vibration felt in the acceleration pedal. My co-worker thinks that it's just because their new rotors and it happens when it's cold or the car has been sitting a while, that it'll stop after some time once they get 'worn in' I guess and more lubricated? I was wondering if anyone else knew what it might be. I took it back to the place that changed the rotors, but of course at that time, the car wasn't making any weird noises, so they said they didn't see anything wrong. Not sure if this is a serious problem or if it will resolve itself over time. Any suggestions? Thank you.

-Theresa Fitzwater

Answer
Sounds like you have rear drum brakes not rotors. Or I could possibly be wrong. Vehicle year came with one or the other. If you do have drums in the back they have springs to keep the shoe form the drum. (pad from the metal contact) If the spring is bad or not installed right then the noise you are suggesting can be caused by that. Some times the suspension spring on rare occasions can make that noise in the front by slamming on the brakes at a high rate of speed. This noise can be a safety concern. The tech that installed these should recheck his work. Good luck.